Tunnel calculations

a circular tunnel is excavated at a distance of 18 ft .from a fault striking along the axis of the tunnel . and dipping 55 as shown in the accompanying drawing determine the normal and shear stresses a long the fault at pint a as well as at points b situated 20 ft down from a and points c. 20 ft above a (both b and c are along the fault ) the tunnel is driven at 1000 ft below surface in a diplomatic rock and k is equal to 2 and y = 150 ib/cft if the sj =0 and @j =25 derg is the a danger of the fault slip at any of the point a b and c